statTally: Tally test statistics

In mosaic: Project MOSAIC Statistics and Mathematics Teaching Utilities

Tally test statistics

Description

Tally test statistics from data and from multiple draws from a simulated null distribution

Usage

statTally(
  sample,
  rdata,
  FUN,
  direction = NULL,
  alternative = c("default", "two.sided", "less", "greater"),
  sig.level = 0.1,
  system = c("gg", "lattice"),
  shade = "navy",
  alpha = 0.1,
  binwidth = NULL,
  bins = NULL,
  fill = "gray80",
  color = "black",
  center = NULL,
  stemplot = dim(rdata)[direction] < 201,
  q = c(0.5, 0.9, 0.95, 0.99),
  fun = function(x) x,
  xlim,
  quiet = FALSE,
  ...
)

Arguments

sample	sample data
rdata	a matrix of randomly generated data under null hypothesis.
FUN	a function that computes the test statistic from a data set. The default value does nothing, making it easy to use this to tabulate precomputed statistics into a null distribution. See the examples.
direction	1 or 2 indicating whether samples in rdata are in rows (1) or columns (2).
alternative	one of default, two.sided, less, or greater
sig.level	significance threshold for wilcox.test used to detect lack of symmetry
system	graphics system to use for the plot
shade	a color to use for shading.
alpha	opacity of shading.
binwidth	bin width for histogram.
bins	number of bins for histogram.
fill	fill color for histogram.
color	border color for histogram.
center	center of null distribution
stemplot	indicates whether a stem plot should be displayed
q	quantiles of sampling distribution to display
fun	same as FUN so you don't have to remember if it should be capitalized
xlim	limits for the horizontal axis of the plot.
quiet	a logicial indicating whether the text output should be suppressed
...	additional arguments passed to lattice::histogram() or ggplot2::geom_histogram()

Value

A lattice or ggplot showing the sampling distribution.

As side effects, information about the empirical sampling distribution and (optionally) a stem plot are printed to the screen.

Examples

# is my spinner fair?
x <- c(10, 18, 9, 15)   # counts in four cells
rdata <- rmultinom(999, sum(x), prob = rep(.25, 4))
statTally(x, rdata, fun = max, binwidth = 1)  # unusual test statistic
statTally(x, rdata, fun = var, shade = "red", binwidth = 2)  # equivalent to chi-squared test
# Can also be used with test stats that are precomputed.
if (require(mosaicData)) {
D <- diffmean( age ~ sex, data = HELPrct); D
nullDist <- do(999) * diffmean( age ~ shuffle(sex), data = HELPrct)
statTally(D, nullDist)
statTally(D, nullDist, system = "lattice")
}

mosaic documentation built on May 29, 2024, 5:27 a.m.